I knew a hippie chick some time back in the last century that used it. (No, not MY hippie chick...)
On herself, on her kid, or both?
The Bedouin Arabs my dad worked with in the 50s plastered their kids' posteriors with a thick layer of fresh, wet camel dung. When it dried out, it was time to 'change the diaper' by cracking it off, and applying a new coating.